Footwear can be designed to provide a variety of stylistic and functional benefits. One of these sought-after utilitarian advantages is comfort of the wearer during various activities. Particularly when walking or running, flexibility and shock absorption of the shoe greatly determine the amount of comfortable support experienced by the wearer. Shoes normally worn for active use, e.g., extensive walking or fitness sports, typically consist of an upper (of canvas, leather or other supple fabric material) joined to an outer sole (of rubber, leather or other durable material) having a bottom that contacts the ground. The inner surface of the outer sole, i.e., outsole, has distinct regions that contact corresponding portions of the wearer""s foot sole. For example, the outsole can have distinct heel, arch and plantar regions that underlie the respective portions of the footxe2x80x94these regions may be specifically adapted to provide a given functional benefit to the parts of the foot that are supported by them. A highly flexible inner sole, i.e., insole, is usually provided that directly contacts the wearer""s foot and is positioned between the foot and the upper surface of the outsole. The insole has an upper surface of fabric or soft leather to give added comfort and breathability to the sole of the foot. The outsole needs to embody both flexible and durable characteristics, to resist wear from pavement and torsional stresses, also to cushion shock from impact due to foot motion.
Others have sought to provided added shock absorption to the outsole by providing added layers or members in various regions of the outsole. For example, U.S. Pat. No. 4,783,910 to Boys, II et al., provides a midsole with discrete heel capsule to cushion G-forces, in conjunction with an anti-torsion heel member. U.S. Pat. No. 1,994,681 to Blumfeld, U.S. Pat. No. 4,245,406 to Landay, et al., and U.S. Pat. No. 5,839,208 to Huang disclose outsoles having inner cavities presenting patterns of ribbed structures that are joined to sides of the outsole. Such structures are said to enhance the shock-absorbing support function of the outsole and its torsional stability.
U.S. Pat. No. 4,794,707 to Franklin, et al., shows a midsole with an internal dynamic rocker element disposed in the forefoot of the midsole, said to enhance walking comfort.
U.S. Pat. No. 4,663,865 to Telecemian has a first set of ribs that extend from within the heel cavity and a second set of ribs extending diagonally through the arch cavity, both sets dovetailing into the floor of the plantar cavity. A resilient cushion is located in the plantar cavity, being shaped and sized corresponding to that cavity. However, the separate cushion does not form an integral part of the inner plantar cavity of the outsole, but rather functions as an integral component of the midsole than of the outsole. Moreover, such a cushion requires additional steps to assemble together with the midsole during the manufacturing process.
Therefore it is desirable to provide a strategically positioned cushioning support member in a strategic functional region of the outsole cavity, which member functions integrally with the outsole in cushioning shock to a given area of the foot.
It is further desirable to provide a cushioning member that is fabricated as part of the inner cavity of the outsole, so that the member is joined thereto and functions integrally with the outsole, versus other components of the shoe during wear.
It is still further desirable to provide an integral cushioning member that functions together with other stabilizing members found within the inner cavity of the outsole.
According to the subject invention, an outer sole of a shoe unit has a peripheral wall delimiting a plantar, heel and arch region of the outsole. A separate, flexible cushioning pad of polymeric material is molded in place within one or more of the heel, plantar and arch regions of the outsole.
In a preferred embodiment, the outsole is made of a flexible polymeric material having a given density and the pad is molded in place within the plantar region, the pad being formed of a different polymeric material th an the outsole, such that the plantar and heel regions are of differing densities, respectively.
In a preferred embodiment, an inner cavity is formed in at least one of the plantar, heel and arch regions, the cavity including a floor. A separate cushioning pad element is located within the cavity, wherein the pad is molded-in-place to the floor within the cavity to form an integral functional part of the outsole.
In a preferred embodiment, the cavity and pad are located in the plantar region of the outsole.
In another preferred embodiment, a plurality of ribs form a structure defining a series of combs that articulate with the peripheral wall of the outsole, the arrangement further delimiting an inner periphery of the cavity, wherein the pad is joined to that inner periphery. In a further preferred embodiment, the cavity and pad are shaped to correspond to the contours of the peripheral walls of the outsole.
In another preferred embodiment, a plurality of ribs form a structure defining a series of open combs that extend transversely across the outsole and articulate with the peripheral wall of the outsole within one or more of the heel, arch and plantar regions. It is further preferred that the pad be molded in place within the combs of the plantar region.
An advantage of the present invention is that a strategically positioned cushioning support member can function in a strategic region of the outsole, as an integral part of the outsole, in cushioning shock to a given area of the foot.
Another advantage of the present invention is that the cushioning member can be fabricated as part of the inner cavity of the outsole, so that the member is joined thereto and functions integrally with the outsole, versus other components of the shoe during wear.
Another advantage of the present invention is an integral cushioning member that functions together with other stabilizing members found within the inner cavity of the outsole.
A further advantage of the present invention is enhanced support and shock absorption by providing an outsole with selected cushioning capacity where needed, without the necessity of a separately engineered midsole assembly.
Other objects and advantages of the present invention will become apparent to those skilled in the art, by a careful examination of the following Specification, Claims and Drawings wherein reference numerals correspond to like descriptions in the Specification.